1. Field of the Invention
The present invention relates to a centrifuge rotor lid and, more particularly, to a method and means for retaining the lid of a centrifuge rotor in contact with the rotor during operation thereof.
2. Description of the Prior Art
A typical centrifuge includes a rotor positioned within a chamber in a housing, the housing having a cover to enclose the chamber during operation of the rotor. A common type of centrifuge rotor includes a yoke which is provided with a plurality of identical, spaced, support arms which extend radially outwardly therefrom and a plurality of swinging rotor buckets supported by trunnion pins disposed at the ends of the support arms. In the case of high speed centrifuges, the chamber is typically evacuated so that the rotor operates in a vacuum. On the other hand, vacuum chambers are not ordinarily used with low speed centrifuges.
Due to the nature of the centrifuging process, i.e. the rotor spinning rapidly in an air environment, a substantial amount of turbulence occurs within the chamber when using swinging bucket-type centrifuge rotors. This turbulence causes heating of the rotor and the sample therein and a substantial drag, increasing the power requirements for driving the rotor.
To minimize this turbulence, it has been proposed to mount a swinging bucket centrifuge rotor in an enclosure which is rotatable therewith and which substantially streamlines the outer surface of the rotor. A typical enclosure includes a wind shield physically connected to the bottom of the yoke and extending beneath the yoke and around the sides thereof and a removable lid which is positionable over the yoke and connectable to the yoke or the wind shield.
While the inclusion of such an enclosure for a swinging bucket-type rotor has had the desired result of decreasing turbulence within the centrifuge chamber, it has created a centrifuge which is inconvenient to use. This is, conventional swinging bucket-type rotors have open buckets which may have samples inserted into the removed therefrom for continuous, rapid operation. Now, however, since prior designs have always physically clamped the lid to the wind shield, it has been necessary to physically disconnect the lid so that it may be removed from the rotor to gain access to the buckets. This procedure has been time consuming and inconvenient and has decreased the productivity of available centrifuges.